Organic EL (Electro Luminescence) devices are attracting attention as a luminescence device taking the place of a light emitting device using a fluorescent light or an LED and have been studied well.
An organic EL device is made by laminating a substrate such as a glass substrate or a transparent resin film with an organic EL element composed of organic compounds and the like. An organic EL element is a light emitting element including an organic light-emitting layer between an anode and a cathode. The organic light-emitting layer is made up of a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer, and the like.
The organic light-emitting layer and electrode layers constituting an organic EL element are formed in a film state using a device such as a vacuum deposition device or a CVD (Chemical Vapor Deposition; chemical vapor phase growth method) device. Therefore, an organic EL device is considerably thin and light compared with a liquid crystal display or an LED lighting equipment. A thin and light organic EL device is, for example, easily attached to a ceiling or a wall and can be used in various ways as a flexible luminescence device. However, wiring for supplying power to the organic EL device is often embedded in a ceiling or a wall, restricting an installation place of the organic EL device depending on a position of wiring. Patent document 1 specified below discloses a power transmission circuit which can supply AC power to a plate-type display panel in a contactless manner.
The power transmission circuit disclosed in Patent document 1 uses a transmitting board for transmitting AC power and a receiving board provided with a display panel. Two planar electrodes are formed on a surface of each of the transmitting board and the receiving board. The planar electrodes of the transmitting board and the receiving board are arranged so as to be opposite each other across an insulating board, thereby generating electrostatic capacitance between the planar electrodes. It can be said that the electrostatic capacitance is a capacitor, via which the transmitting board and the receiving board are electrically connected (hereinafter referred to as a capacitive coupling method). As a consequence, AC power is supplied from the transmitting board to the receiving board even though they are not connected via wiring or the like.
Furthermore, Patent documents 2 and 3 specified below disclose an electrical energy transmitting device which can supply power by other capacitive coupling methods.